Use Stage Embodied Carbon (B1-5) in OneClick for North America

LCA Data & Tools
#1

Hi all,
I was wondering if anyone had experience measuring the embodied carbon of the Use Stages (B1 to B5) in OneClick LCA for North American projects?

Stage B1 (use phase) can be measured under the “emissions and removals” query, under which refrigerant emissions, concrete carbonisation, and vegetation carbon withdrawals can be calculated. How do we go about estimating these quantities?

OneClick does not provide an option to calculate Stage B2 (maintenance phase), and when we reached out to them we were told that in some schemes this can be estimated based on the fuel used by cars which have to drive to locations to maintain things, or as a percentage of B3 emissions, however neither estimations provide really reliable data. Has anyone used this method or a different one?

Lastly, is there a rule-of-thumb for the repair rate of typical building materials? This is required for Stage B3 (repair rate phase).

Any information would be greatly appreciated!

#2

Hi Natasha,

Sorry, I’m not familiar with OneClick, but thought I’d respond with more generic observations.

B1. A formula for calculating sequestration through concrete carbonisation can be found in the European standard EN 16757.
B1: Vegetation carbon withdrawals would be difficult to estimate accurately given the endless number of scenarios. I would suggest to use a high-level estimate for the type of vegetation and climate zone of the building if possible. Not sure if others can point you to appropriate literature sources.
B2/B3: Normally you’d include the fuel for maintenance vehicles, e.g. if you have a road maintenance vehicle that is required for periodic inspections of the road, then it would have to be included. Fuel in cars for staff that undertake the repairs (or maintenance for that matter) would not be within scope I’d imagine, unless you also include transport of people living or working in the building (e.g. commuting emissions). If you have a repairperson coming to the building to replace a broken circuit in an elevator, it becomes somewhat of a grey area. It comes down to what the objective of your carbon footprint is as to whether you should include it.
B3: The repair rates are often difficult to establish, as they are generally not planned. Some manufacturers would have data on their product if they also manage maintenance (e.g. for garage doors), but generic data are difficult to find. At a material level, some materials (e.g. concrete) normally don’t require repair, while others (e.g. glass windows) are more likely to require repair during the life of the building. I find it is often most important to be transparent in the choices, rather than trying to be accurate…

Hope it helps.

Regards,
Rob

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